Tolerance to cadmium in the germination and development of jack beans

Abstract

Cadmium (Cd) is a metal that contaminates the environment mainly through agroindustrial, metallurgical and chemical industrial activities. It can affect mineral absorption by plants, the stomatal aperture, photosynthesis and water balance by reducing the crop yield. Aiming at the discovery of new species able to tolerate Cd, this study evaluated the germination and development of jackbean plants in the presence of Cd to determine whether there is tolerance to this metal. Seeds and seedlings of this species were grown in plastic pots containing sand with Cd concentrations of 0, 500 and 2000 µmol L -1 applied as CdCl 2 .2.5H 2 O. The experiments were conducted in a greenhouse under natural photoperiod conditions. Percent germination was close to 100% 13 days after sowing. Seedlings accumulated much of the applied Cd in the shoot and produced high biomass. No alterations to the photosynthetic apparatus were observed at the lower concentrations. This indicates that jack bean plants exhibit characteristics of tolerance to Cd and that further studies should be performed to report if this species can be used as phytoremediator. RESUMO: O cádmio (Cd) é um metal que contamina o ambiente principalmente por meio das atividades agroindustriais, metalúrgicas e químicas. Ele pode afetar a absorção de minerais pelas plantas, a abertura estomática, a fotossíntese e o balanço hídrico diminuindo a produção vegetal. Visando à descoberta de novas espécies capazes de tolerar o Cd

Cadmium Tolerance During Seed Germination and Seedling Growth of Schinus molle (Anacardiaceae)

“…In fact, Cd can reduce seedling biomass production (Ali et al, 2015;Anuradha & Rao, 2007;Chugh & Sawhney, 1997), and root and shoot lengths (Chugh & Sawhney, 1997;He et al, 2008;Tao et al, 2015). Even tolerant species can show reduced seedling growth depending on the Cd concentration experienced (Rossi et al, 2012). In this study, S. molle seedlings maintained their overall growth under conditions of Cd contamination, and some growth parameters even increased.…”

“…well-known (Ali et al, 2015;Bautista et al, 2013;Chugh & Sawhney, 1997). However, Cd tolerance in seeds depends on both their genotypes (Ahmad et al, 2012) and the concentration of the pollutant (Rossi et al, 2012). The number of species known to be Cd accumulators is remarkably lower when change in this study and the overall root anatomy was preserved, no real signs of Cd toxicity were evident in the roots of the S. molle seedlings examined.…”

“…Mature S. molle plants proved to be tolerant to Cd and Pb in previous studies and could accumulate most of the Pb to which they were exposed in their roots (Pereira et al, 2013(Pereira et al, , 2016. Moreover, Cd accumulation in the roots has been reported in several different plant species (Rivera-Becerril et al, 2002;Rossi et al, 2012). A plant's capacity to limit heavy metal transport from the roots to the shoot is related to the thickening of root cortex and endodermis (Pereira et al, 2013;Ribeiro et al, 2015).…”

“…Cd toxicity is high during seed germination and may decrease seed vigor (Ahmad et al, 2012;Ali et al, 2015;Anuradha & Rao, 2007;Bautista et al, 2013;He et al, 2008;Tao et al, 2015;Zhang et al, 2012). However, some species can overcome Cd's negative effects, depending on variations in their genotypes or pollutant concentrations (He et al, 2008;Rossi et al, 2012;Tao et al, 2015). Likewise, the growth of roots and shoots of seedlings are both reduced by Cd in sensitive plant species (Anuradha & Rao, 2007;Bautista et al, 2013;Tao et al, 2015;Zhang et al, 2012).…”